Moshe Rabeinu is always saying to the Yidden: Why are you going to me? Go to Hashem! The Seforno explains that believing in a human being is K'fira, and that’s why Yaakov told Rachel when she asked for children: הֲ תַ חַ תֵֵא לֹקִׁ יםֵאָ נֹּכִׁ יֵֵלֵב “Am I Hashem?? You shouldn’t believe in a human being!” It seems that Rachel accepted his words, and her son Yosef used the exact same phrase (when the brothers came to him in Parshas Vayechi to become his slaves) הֲ תַ חַ תֵ א לֹקִׁ יםֵאָ נִׁ יֵֵנֵיט Don’t worry (from any evil that you are afraid I may do to you) since a human is powerless, and Hashem is the only one who controls the world.
This is what Moshe is saying to the Yidden: You must believe in the power of a human being only in regards to overcoming his Yetzer Hara, but in regards to providing your needs you may not rely on a human being. Moshe says: וְנַחְ נוֵּמָ הֵֵטזֵז We are nothing. This is a lesson that even if you are dealing with the Gadol HaDor, it is always Hashem. That’s why when Shim’i cursed him, Dovid said: כִׁ יֵה'ֵאָ מַ רֵלוֵֹקַ ל לֵֵש"בֵֵטזֵֵי It’s all Hashem. The same applies when someone does you a favor, it’s from Hashem.
